The power of two: epigenetics and twins

THG epigenetics blog post

This blog post was written by Jeff Craig

Special Epigenetics issue of Twin Research and Human Genetics

Twins are at the forefront of research into human health and disease. Twin Research and Human Genetics has published a Special Section highlighting how researchers have learned how epigenetics, the molecules that play the symphony of life on our genes, can influence our future health. Never before have such a group of papers been brought together in a single issue.

Papers highlight the power of sampling the same twins over time as their health changes and others detail the ways in which researchers scour the human genome for evidence of epigenetic associations with disease.

Four of the papers focus on the discordant identical twins in which only one twin has an illness. Topics span a wide age range of subjects, from birth weight to hormone replacement therapy (HRT). One even focuses on whether twins are “morning” or “evening” people.

Three papers from the Netherlands Twin Registry highlight the power of collecting biological samples from many hundreds, even thousands, of twin pairs. These are studies of aggressive behaviour, tic disorders and wellbeing and pinpoint specific epigenetic differences linked with each.

The final paper looks at the influences, both genetic and environmental, on how we age epigenetically.

In summary this special section is a clear snapshot of cutting edge twin research that is relevant for our hunt for the genes that influence all of our health.

You can read the articles included in this Special Section free of charge for a limited time here, or using the individual articles linked below.

See below for more details about the papers included in this special issue:

Read the full editorial from Jeff Craig and Richard Saffery, The Power of Two: Epigenetics and Twins

Chiarella et al: “This paper reviews the literature showing how monozygotic twin designs can be used to study epigenetic mechanisms that may explain the impact of early in utero and postnatal environmental factors on the development of psychopathology. “

Tsai et al: “this study of adult identical twins born with different weights found a biological legacy in a gene involved in fetal growth. This suggests that the environment we encounter in the womb can influence us for many year after.”

Bahl et al: “using twins discordant for hormone replacement therapy (HRT) the authors showed that HRT can change the activity of genes in the blood and that many of these genes were associated with sense of smell. This makes sense as HRT is known to improve a woman’s sense of smell.”

Wong et al: “believe it or not, some identical twins are more “day people” while their twin brither or sister are “night people. This study showed that our preference for day or night could be programmed in ‘epigenetic’ factors that stick to our genes and change their activity”

Du et al found an ingenious way to tell which of a pair of identical twins a sample found at a crime scene came from. Identical Twins cannot be distinguished because of their identical DNA but these researchers used “epigenetics”, factors that sit on top of the DNA”.

Bui et al: “identical teenage twins that had separate placentas in the womb may have a greater difference in the activity of their genes than those who shared a placenta. This shows that the environment we encounter in the womb can have long lasting effects”

Zilhao et al and van Dongen et al: “These twin studies of both tic disorders and aggressive behaviour identified changes to gene activity in the blood in genes related to brain function, suggesting that looking at the blood may reveal information about how such disorders are caused.”

Baselmans et al: “study showed that wellbeing in twins is associated with factors that control gene activity.“

Li et al: “study suggests that the variation in methylation acceleration due to unmeasured genetic factors is likely to be even lower that the 40% estimated in previous studies”

Successful aging at 100 years

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Images: Participants from the PT100 – Oporto Centenarian Study being interviewed

The February International Psychogeriatrics Article of the Month is entitled “Successful aging at 100 years: the relevance of subjectivity and psychological resources” by Lia Araújo, Oscar Ribeiro, Laetitia Teixeira and Constança Paúl. This blog piece was written for us by one of the paper’s authors, Lia Araújo.

Successful aging is a desire that we all aspire for ourselves and for our loved ones. According to Rowe and Kahn’s definition, operationalized through the MacArthur study, individuals who met the three criteria of (i) avoiding disease and disability, (ii) high cognitive and physical functioning and (iii) engagement with life were identified as “successful agers”(1).

Another wish common to many of us is to live longer, why not up to 100!? Indeed, this can be a dream come true for an increasing number of individuals, since the oldest generations are becoming more representative and centenarians are likely to become more common(2).

Both wishes conjointly, a longer and successful aging, motivated the development of the PT100 – Oporto Centenarian Study(3). This population-based study was conducted in the north region of Portugal and included 140 centenarians who were interviewed face-to-face. We began to question ourselves what it means to be “successful” at such an advanced age and quickly got to ask the same question to our study participants. What we found was that sometimes the most relevant outcomes are from the perspective of the subjects themselves; and that together with the concern for problems and needs, we must capitalize on the real strengths of older people.

The criterion of little or no age-related decrements in physiologic function for those aging successfully does not apply to centenarians. However, when considering alternative criteria, based in centenarian´s self-perceptions of health, functional and cognitive capacity, a higher proportion of centenarians might be considered as successful. The paper also presents the influence of the available resources, such as individual strategies and external support, in improving subjective appraisals of successful aging, which confirms that certain internal resources (e.g., self-efficacy and purpose) are not overwhelmed by physical deterioration and may even gain power when corresponding and meaningful perceptions of oneself and one´s life are maintained in late life.

Successful aging at very advanced ages may not mean to stay healthy for even longer but rather to adapt. With that in our minds, as individuals, families, researchers, professionals or policy-makers, longer lives can and will be associated with improved quality of life in all ages and our wishes can become reality for our and next generations.

The full paper “Successful aging at 100 years: the relevance of subjectivity and psychological resources” is available free of charge for a limited time here.

The commentary paper “Success at 100 is easier said than done – comments on Araújo et al: successful aging at 100 years” by Peter Martin and Leonard W. Poon is also available free of charge here.

References
1. Rowe, J.W., & Kahn, R.L. (1997). Successful aging. Gerontologist, 37, 433-440.
2. Serra, V., Watson, J., Sinclair, D., & Kneale, D. (2011). Living Beyond 100: a report on centenarians. London: International Longevity Centre – UK.
3. http://www.pt100.pt

Turns Out Birth Order Might Not Mean Much

In a curious turn of events, according to a new study by a University of Illinois study birth order actually has no significant effect on personality or intelligence between siblings. The study analyzed 377,000 high school students and its head researcher is calling it the biggest look at the relationship between personality and birth order in history.

Strobist: SB-800 camera right with Honl 5 inch snoot aimed at girl. SB-800 with 8 inch shoot aimed at boy. Both at 1/2 power.

Strobist: SB-800 camera right with Honl 5 inch snoot aimed at girl. SB-800 with 8 inch shoot aimed at boy. Both at 1/2 power.

The study was published in the Journal of Research in Personality and has established that while first-borns statistically have a one-point IQ advantage over their younger siblings the difference is “statistically significant but meaningless.”

The lead researcher, Brent Roberts, stated, “In some cases, if a drug saves 10 out of 10,000 lives, for example, small effects can be profound. But in terms of personality traits and how you rate them, a .02 correlation doesn’t get you anything of note. You are not going to be able to see it with the naked eye. You’re not going to be able to sit two people down next to each other and see the differences between them.”

Birth order has been a fixture of fascination and often is linked closely with fate; firstborns are meant to be controlling and ambitious, middle children are meant to be wayward and rebellious and oft overlooked, and the youngest are coddled, bratty, and babied. The firstborn traditionally has the most weight on his shoulders and inherits the most of the family’s fortune or tribulations. For decades, scientists have been studying the effects of birth order on family dynamics and individual personalities from early 20th Century Austrian psychiatrist Alfred Adler to pop phycology parenting books on how to raise each child based on their place in the family.

The study controlled for a few factors, most notably family size, socio-economic status, and gender and arrived at a .02 correlation between birth order and personality and a .04 correlation between birth order and intelligence.

This shockingly low number goes against almost all previous studies and hypotheses regarding personality and intelligence relative to birth order.

It’s tempting to credit and blame a child’s personality traits, characteristics, and fate on birth order. The reality however is so much more complex; each child’s character and fate are based on biology and environment and encompass hundreds of thousands choices in and out of his control. The study’s co-author, Rodica Damian, sums it up nicely, “Birth order probably should not influence your parenting because it’s not meaningfully related to your kid’s personality or IQ.”

Links:

http://www.chicagotribune.com/lifestyles/ct-birth-order-no-effect-balancing-20150720-column.html

http://www.forbes.com/sites/daviddisalvo/2015/07/20/despite-popular-assumptions-birth-order-isnt-important-says-new-study/

Cambridge launch new open access journal – Global Health, Epidemiology and Genomics

GHG blog image - cover

Cambridge unveils new Open Access journal – Global Health, Epidemiology and Genomics (GHEG)

Cambridge University Press is delighted to announce a major new open access journal, Global Health, Epidemiology and Genomics (GHEG), dedicated to publishing and disseminating research that addresses and increases understanding of global and population health issues through the application of population science, genomics and applied technologies.

Global Health, Epidemiology and Genomics is the Press’s second Open Access journal in the field of global health, joining Global Mental Health which launched in 2014. Spanning both non-communicable and communicable diseases, GHEG will specifically integrate epidemiology, genomics and related technological advances in the global health context. Topics relevant to GHEG will include studies, methods and resources relating to global population health, disease aetiology, variation in disease susceptibility, drug resistance and surveillance, health care and health care systems, pharmacogenomics and stratified medicine, as well as the challenges of implementing new developments into clinical practice and the community, globally. In addition to more traditional Original Research and Review Articles, GHEG will support submission of Resources and Analyses that provide a framework for integrating and facilitating genomics and global health studies.

The Editor-in-Chief of GHEG is Dr Manjinder Sandhu, head of the Global Health Group based at the University of Cambridge and the Wellcome Trust Sanger Institute. The international Editorial team includes recognised leaders in global health, epidemiology and genomics from around the world who have taken a lead in shifting attention and action to global health and populations, as well as a wider Editorial Board that will reflect and emphasize the broad scope of the field.

Dr Sandhu said, “I am committed to making GHEG an innovative, engaging and practical resource for the global health research community through which we can publish new scientific research, exchange ideas within and across our related disciplines and share resources to facilitate efforts to increase our understanding of human health and shape effective disease management worldwide.”

Professor Alex Brown, Deputy Director of the South Australia Health & Medical Research Institute (SAHMRI) and one of the journal’s Associate Editors commented, “I am delighted to be involved with GHEG, an exciting venture which recognises the relevance and importance of the work being undertaken in the field of global health, epidemiology and genomics and the widespread benefits to be gained by applying technological advances and innovations to research into population health including within disadvantaged population groups. By facilitating discussion and encouraging the sharing of resources GHEG looks to actively support contributions in these areas.”

Katy Christomanou, Publishing Director for STM Journals at Cambridge University Press, added, “This launch affirms our long-term commitment in the global health field and reflects our strong investment in maintaining and extending our successful presence in this area. We are highly enthusiastic at the prospect of working alongside such an outstanding editorial team.”

Global Health, Epidemiology and Genomics will be hosted on Cambridge’s industry-leading platform, Cambridge Journals Online (CJO). The Journal will benefit from a range of the latest author services including article level usage metrics and Altmetric data. In addition, for articles submitted during 2015 and 2016, Cambridge University Press will waive all article processing charges.

For more information please visit the journal website: journals.cambridge.org/gheg

 

Cambridge launch new open access journal – Global Health, Epidemiology and Genomics

GHEG cover_final2

Cambridge unveils new Open Access journal – Global Health, Epidemiology and Genomics (GHEG)

Cambridge University Press is delighted to announce a major new open access journal, Global Health, Epidemiology and Genomics (GHEG), dedicated to publishing and disseminating research that addresses and increases understanding of global and population health issues through the application of population science, genomics and applied technologies.

Global Health, Epidemiology and Genomics is the Press’s second Open Access journal in the field of global health, joining Global Mental Health which launched in 2014. Spanning both non-communicable and communicable diseases, GHEG will specifically integrate epidemiology, genomics and related technological advances in the global health context. Topics relevant to GHEG will include studies, methods and resources relating to global population health, disease aetiology, variation in disease susceptibility, drug resistance and surveillance, health care and health care systems, pharmacogenomics and stratified medicine, as well as the challenges of implementing new developments into clinical practice and the community, globally. In addition to more traditional Original Research and Review Articles, GHEG will support submission of Resources and Analyses that provide a framework for integrating and facilitating genomics and global health studies.

The Editor-in-Chief of GHEG is Dr Manjinder Sandhu, head of the Global Health Group based at the University of Cambridge and the Wellcome Trust Sanger Institute. The international Editorial team includes recognised leaders in global health, epidemiology and genomics from around the world who have taken a lead in shifting attention and action to global health and populations, as well as a wider Editorial Board that will reflect and emphasize the broad scope of the field.

Dr Sandhu said, “I am committed to making GHEG an innovative, engaging and practical resource for the global health research community through which we can publish new scientific research, exchange ideas within and across our related disciplines and share resources to facilitate efforts to increase our understanding of human health and shape effective disease management worldwide.”

Professor Alex Brown, Deputy Director of the South Australia Health & Medical Research Institute (SAHMRI) and one of the journal’s Associate Editors commented, “I am delighted to be involved with GHEG, an exciting venture which recognises the relevance and importance of the work being undertaken in the field of global health, epidemiology and genomics and the widespread benefits to be gained by applying technological advances and innovations to research into population health including within disadvantaged population groups. By facilitating discussion and encouraging the sharing of resources GHEG looks to actively support contributions in these areas.”

Katy Christomanou, Publishing Director for STM Journals at Cambridge University Press, added, “This launch affirms our long-term commitment in the global health field and reflects our strong investment in maintaining and extending our successful presence in this area. We are highly enthusiastic at the prospect of working alongside such an outstanding editorial team.”

Global Health, Epidemiology and Genomics will be hosted on Cambridge’s industry-leading platform, Cambridge Journals Online (CJO). The Journal will benefit from a range of the latest author services including article level usage metrics and Altmetric data. In addition, for articles submitted during 2015 and 2016, Cambridge University Press will waive all article processing charges.

For more information please visit the journal website: journals.cambridge.org/gheg

Male sexual orientation influenced by genes

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Results of a five-year study of 409 independent pairs of homosexual brothers in 384 families find that genetics play a key role in male sexual orientation. Alan Sanders, M.D., a psychiatrist who studies behavioral genetics at NorthShore University HealthSystem Research Institute, was the principal investigator of the molecular genetics study that scanned the entire human genome to search for evidence of genetic links to variation in sexual orientation in men.

“We found two strong links in chromosome 8 and chromosome Xq28, which supports that this is not a one-gene, one-trait scenario,” said Dr. Sanders. “These genetic variations contribute to the development of the important psychological trait of male sexual orientation.

The new evidence “is not proof but it’s a pretty good indication” that genes on the two chromosomes have some influence over sexual orientation.”

Participants in the study were gay men with at least one living gay brother (full brothers, half brothers or fraternal twins). They were asked to provide DNA samples through blood or saliva and to complete a questionnaire about their sexual and personal history and that of immediate family members. The study was funded by the US National Institutes of Health from the National Institute for Child Health and Human Development.

“Understanding the origins of sexual orientation enables us to learn a great deal about sexual motivation, sexual identity, gender identity and sex differences,” Dr. Sanders added.

The full paper, “Genome-wide scan demonstrates significant linkage for male sexual orientation”, which is published in Psychological Medicine can be read free of charge for a limited time here.

Expert Reviews in Molecular Medicine launches ‘Discovery’ section

ERM Cover final

Expert Reviews in Molecular Medicine launches ‘Discovery’ section and welcomes original research under a gold Open Access extension.

We have launched the ‘Discovery’ section within our journal Expert Reviews in Molecular Medicine (ERMM) and now welcome high-quality, innovative original research papers to complement its authoritative ‘Reviews’ section. Authors who wish to publish their papers in ‘ERMM: Discovery’ will be able to do so under a gold Open Access model and payment of an article processing charge (APC). Reviews will continue to be accessed via a subscription to ERMM, with Open Access as an option for Review authors to choose should they wish to pay the APC.

ERMM has been publishing high-quality peer-refereed review articles since late 1997, which have proved a valuable forum for authoritative reviews in the area of molecular medicine. The Journal has an impressive Impact Factor of 6.628 (2012), which places it in a strong position amongst its competitors and this expansion will provide readers and authors with an enhanced resource for molecular medicine research.

ERMM: Discovery will be overseen and edited by Dr Julian Sale who will be working alongside the Editor-in-Chief, Professor Timothy Cox.

“We are delighted that Cambridge University Press has decided to enrich its portfolio of contemporary biological science by taking this publication initiative; it will incorporate new pages of experimental research to synergise with Expert Reviews. We welcome this innovative step and greatly look forward to receiving fresh discovery science in molecular medicine for competitive publication.”

Molecular medicine as a broad definition refers to elucidating the pathogenesis of disease at the molecular or physiological level, which may lead to the design of specific tools for disease diagnosis, treatment or prevention – this highlights the timeliness and importance of the Journal in the field. ERMM: Discovery will publish original work from across the full breadth of molecular medicine and pathology. Its scope mirrors that of ERMM: Reviews focussing on the molecular mechanisms of disease, diagnostics and therapy. The Journal particularly invites original research papers which provide mechanistic insights, while papers of a purely descriptive or correlative nature and case reports are unlikely to be accepted unless they provide exceptional scientific insight.

The Editors are inviting high-quality contributions of original research for ERMM: Discovery andreview papers for ERMM: Reviews. For detailed instructions on how to prepare your submission, please see our Instructions for Contributors.

Content from Expert Reviews in Molecular Medicine can be viewed atjournals.cambridge.org/erm. A subscription will be required to access Review articles but all Discovery articles will be freely available under an OA license and are not included in the subscription price. All Open Access articles in this journal have article level metrics available.

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